CEDAR BLUFF, Alabama (CNN) -- Six years after an unsolved double murder in Alabama, authorities there reasserted Friday that Mark Barton -- the central figure in a deadly shooting rampage in neighboring Georgia -- was still their prime suspect in the 1993 case.

Barton's first wife, Debra Spivey Barton, 36, and her mother, Eloise Spivey, 59 were hacked to death with a sharp object at a campground in Alabama's Cherokee County, about 100 miles west of Atlanta.

No charges were ever filed in the case, but Barton was the lone suspect, based on circumstantial evidence, authorities said.

"We were never able to get enough evidence to carry to the grand jury and convict the man," Cherokee County Sheriff Ray Wynn told CNN on Friday. "We were hoping we could get a little bit more (evidence) and I felt like if we could get another item or two, that we might have been able to convict him."

Barton had reportedly taken out a $600,000 life insurance policy on his first wife before her murder

Cherokee County District Attorney Mike O'Dell said Thursday that authorities had a suspect in the case, but said he "can't confirm or deny" the suspect was Barton. O'Dell added that investigators made sure they kept up with Barton's whereabouts.

The bodies of the two women were found at Riverside Campground on Weiss Lake in northeast Alabama. They had been staying in a camper without Barton during Labor Day weekend.
The camper showed no signs of forced entry.

Police said the killer dumped the older woman's purse and took two rings, but ignored other jewelry and an envelope containing $600.

Mrs. Spivey's .32-caliber revolver lay on the kitchen counter.

At the time, investigators said there was evidence that Barton was having an affair and had taken out a $600,000 life insurance policy on his wife.

Barton, 44, shot himself to death Thursday as police closed in on him at a gas station in a northern Atlanta suburb following a shooting rampage at two Atlanta office buildings that left nine people dead.

In the days leading up to the shootings, he also is believed to have bludgeoned his second wife and two children in Stockbridge, Georgia, south of Atlanta, taking the Georgia death toll to 13.

Georgia authorities said that, in notes found with the bodies in Stockbridge, Barton denied he was the killer in the Alabama case.

A few months after the Alabama slayings, Mrs. Spivey's husband told the Atlanta Journal-Constitution that "until the murders, Mark was the perfect son-in-law."

"Since then, we have cooled tremendously toward each other," said Bill Spivey, a retired Federal Aviation Administration supervisor. He said Barton had refused to take a polygraph test.

Marty Powell, a cousin of Barton's first wife, said he last saw Barton at the funeral of the two victims and described him as "colder than a cucumber."

"Everybody in the family thinks it was him," he said Thursday. "If they had stopped him then, there would be 12 more people alive tonight."